1. Field of the Invention
The present invention relates to an upper swing body of an excavator, and more particularly, to an upper swing body of an excavator, wherein a rear protrusion is minimized to reduce an operating radius and a cooling performance is improved even in a narrow engine room.
2. Description of the Related Art
An excavator is construction equipment used for excavating earth/sand or aggregate, loading earth/sand or aggregate on a vehicle, or compacting the ground. As shown in FIG. 1, a conventional type excavator comprises a lower traveling body (100) provided with a traveling apparatus, and an upper swing body (110) rotatably mounted on the lower traveling body (100) and provided with a cab (111) and an operating apparatus. In addition, since an engine serving as a power source is provided in the upper swing body (110), an engine room is required as a space for arrangement of the engine. An outer shell of the engine room is defined by an engine room cover (113). Furthermore, a counterweight for maintaining weight balance for the operating apparatus should be provided in the upper swing body (110).
As described above, a number of components should be disposed in the upper swing body (110). Requirements for arrangement of these components are as follows.
First, in order to smoothly perform the tasks of excavating earth/sand or aggregate, loading earth/sand or aggregate on a vehicle, or compacting the ground, the operating apparatus should be located at a foremost portion of the upper swing body (110). Further, it is preferred that the cab (111) in which an operator sits and manipulates the operating apparatus be disposed at a front side of the upper swing body (110) to secure a front visual field of the operator. Accordingly, the engine room is inevitably disposed at a side or rear of the cab (111) in the upper swing body (110). Considering the balance of a weight distribution, the occurrence of operation noise/vibration and easy access for maintenance, however, it is desirable to arrange the engine room at the rear of the cab (111). Even in the excavator shown in FIG. 1, the engine room is arranged at the rear of the cab (111), i.e., a rearmost portion of the upper swing body (110). Meanwhile, not only an engine and various parts for running the engine but also a radiator for use in cooling the engine and an oil cooler for cooling a working oil are arranged in the engine room. Accordingly, the engine room should have a space with a certain volume, and thus, the engine room is formed to protrude toward the rear of the upper swing body (110). That is, the engine room becomes a rear protrusion of the upper swing body (110). Since the protrusion exists at a rear portion of the upper swing body (110), a swing radius of the upper swing body (110) is increased. Accordingly, a larger operating area is required for such an excavator having a protrusion formed at a rear portion of an upper swing body. So far as the size of the engine is not reduced, there is limitation on simple reduction in the volume of the engine room to minimize the rear protrusion of the upper swing body. Further, since the reduction in the volume of the engine room makes the arrangement of the radiator or oil cooler very difficult, there is a problem in that cooling performance for the engine or the working oil may be lowered.